Keep in mind that a minimum height with the 440 can be measured with straight up shots of the highest twigs, and if your sine measurement falls short of that, probably something is not right, possibly the angle, or the choice of highest twig. I live near Bob and will be back in MA in early May.

Jared-I'll second Bob's recommendation for Theodolite (a very powerful app!) for it's clinometer (based on the iPhones' accelerometers).

And I'll add another app, more specifically addressing angular measure, called "Clinometer". It can measure angles more accurately than you can handhold the iPhone, and while you don't need to use a tripod, you can benefit from its use.

I was given a Samsung smartphone model GT-i5510M with a 2 gb sd card, 87 M internal memory left and Android 2.2.2. It has no cell service but has wi-fi access to the web.

I am a nube to smartphones\ cell phones. I can see how they can be addictive. I checked with a tech guy to see if I could read science journal pdfs but we didn't get much. resources are limited on such phones.

I saw clinometer apps mentioned here and wondered if there is anything worth while for this old phone. A quick check showed the ink above for Requires Android2.2 and up

The material in Measurement and Dendromorhometry, Tree Measuring Guidelines, and Dendromorphometry Toolkit covering measuring tree height is endless. I assume that you are asking what kind of estimating methods could be used with nothing but available smartphone apps and a tape measure. Is that basically the question? We can help, just want to narrow down the subject to exactly what you want.

Bob

Robert T. LeverettCo-founder and Executive DirectorNative Native Tree SocietyCo-founder and PresidentFriends of Mohawk Trail State Forest

I assume that you are asking what kind of estimating methods could be used with nothing but available smartphone apps and a tape measure. Is that basically the question? We can help, just want to narrow down the subject to exactly what you want.

There are basically 4 approaches to measuring tree height: (1) direct measurements with poles and/or tape drops, (2) measurements employing the principle of similar triangles, (3) measurements employing right triangle trigonometry, and (4) measurements using photogrametric techniques and computer software. We could add a 5th, which would be any combination of the 4, but that's kind of a no-brainer.

For minimal equipment, poles for #1 and a tape and yardstick for #2 represent the minimum equipment investments. Most beginners are introduced to #2. It is discusses in the AF Tree-Measuring Guidelines. Its big drawback is loss of accuracy for complex forms. Nonetheless, it can get you into the ball park. Approach #3 takes many routes and involves equipment as simple and inexpensive as a tape measure and a $3.00 iPhone app. However, accuracy is sacrificed for large/tall/complex-shaped trees. If you can afford a $100.00 laser rangefinder to go with a $3.00 iPhone app, you are in business. Again, the AF Tree-Measuring Guidelines spell it all out. It is relatively easy to spell out the steps to go with any single technique. One doesn't have to wade through the 86-page guide. The challenge is to understand the strengths and weaknesses of each method and how to numerically evaluate errors. This gets you into increasingly rarified measuring atmosphere. However, I think you understand that you belong to THE elite tree-measuring organization in the country.

Let us know where you want to go next.

Bob

Robert T. LeverettCo-founder and Executive DirectorNative Native Tree SocietyCo-founder and PresidentFriends of Mohawk Trail State Forest

That source is a very good one. Another is the official Tree-Measuring Guidelines from American Forests. If these documents seem too much, here is a simple technique that you can use to get you into the ball park.

This method suffers from the same weakness as the Tangent Method, but with practice, it can be done in a way to get you a fair estimate of height for many trees, and works pretty well for straight-trunked conifers. If you are interested in pursuing it, let us know and we can give you pointers on how to refine the use of the method.

Bob

Robert T. LeverettCo-founder and Executive DirectorNative Native Tree SocietyCo-founder and PresidentFriends of Mohawk Trail State Forest